Co and N co-doped hierarchical porous carbon as peroxymonosulfate activator for phenol degradation via nonradical pathway mechanism

Developing catalysts with high metal utilization rates for activation of peroxymonosulfate (PMS) has attracted extensive attention. Herein, Co and N co-doped hierarchical porous carbon (Co/HOPNC) was synthesized successfully for peroxymonosulfate (PMS) activation to degrade phenol. Transmission Electron Microscope (TEM) confirmed that this hierarchical porous carbon indeed offered a site for the highly dispersed with low doping amount of Co. The 1.5 % Co/HOPNC exhibited the optimal removal efficiency and admirable adaptability to pH, temperature and different co-existing ions, which was credited to the highly dispersing Co atoms. Furthermore, the leaching of Co showed a neglectable impact on catalytic efficiency, revealing metal leaching was indeed inhibited. Remarkably, singlet oxygen (1O2) and high-valence Co-oxo species were verified as major contributors to enhance the catalytic activity. This finding gives a unique insight in PMS activation mechanism triggered nonradical pathways of hierarchical porous carbon materials. Moreover, the 1.5 % Co/HOPNC displayed an outstanding effect on phenol degradation in actual wastewater which expressed great potential in practical applications.